1. Field of the Invention
The invention relates in general to a method for detecting a size of an optical disk and ejecting the optical disk, and more particularly to the method for detecting size of an optical disk and ejecting the optical disk quickly using the reflecting light received by the optical pickup head.
2. Description of the Related Art
In the main stream of the optical disk drive, the mechanisms for carrying the disk can be divided into a slot-in type drive and a tray type drive. The most common seen diameter lengths of the disks are 8 cm and 12 cm. Typically, the immediate ejection of the disk is performed according to the default value of the program presetting in the optical disk drive. When an 8 cm-disk is inserted into the slot-in type drive and would like to be ejected immediately, the disk drive would eject the disk according to the default value of the program built-in drive. If the default value is 8 cm, the ejection procedure will be normal. However, if the default value presetting in the drive is 12 cm, which means the ejection length is longer than 8 cm, the 8 cm-disk may fall from the drive and be damaged. If a 12 cm-disk is inserted into a slot-in type drive with the default value of 8 cm, the ejection length (i.e. 8 cm) is insufficient for 12 cm-disk, which makes the disk trap in the slot-in type drive.
Refers to FIG. 1, a flow chart of a conventional method for detecting an optical disk is shown. First, an optical disk is loaded on the drive, as shown in the step 101. Then, the traverse module is flushed in the step 103. In the step 105, the optical disk is clamped tightly. Next, an optical pickup head moves from the outer side of the track to the inner side of the track in the step 107. In the step 109, the spindle motor of the drive is driven to rotate the optical disk. Next, the data of the optical disk is read and decoded using the laser light in the step 111. Since the weights and inertia momentum of the 8 cm-disk and the 12 cm-disk are different, the 8 cm-disk and the 12 cm-disk have different angular velocities during the rotation. When the step 111 is performed, the disk can be distinguished by the slot-in type disk drive according to its own angular velocity. According to FIG. 1 and the related description above, it requires several steps to tell the size of the disks correctly, which is time-consuming. In addition, a scraped optical disk loaded on the slot-in disk drive may have an effect on the rotation; thus, the dick would be mis-decoded and wrong information of the disk is obtained.